Magnetic resonance imaging (MR imaging) is used in medical diagnostics to create image data of a layer or an area from inside a human or animal body. In MR imaging a strong and uniform static magnetic field of 0.2 to 3 Tesla in size or greater is required. Such magnetic fields, in particular with high field strengths from 1 Tesla, are produced by superconducting magnets. Usually the superconducting magnet is of hollow cylindrical design, a cylindrical patient tunnel being embodied inside the hollow cylinder. Also arranged in the hollow cylindrical interior of the superconducting magnet are gradient coils for position encoding of the magnetic resonance signals and high frequency antennae for excitation and also for receiving the magnetic resonance signals. The numbers of modules required for MR imaging make the patient tunnel which is already not very large in diameter even narrower.
For image recording a patient is required to remain inside the tunnel-shaped interior of the magnet ideally without moving. Whilst recording magnetic resonance images a significant amount of cooperation is required from the patient and during the recording of images a high level of noise is produced from the switched gradient fields in interaction with the constant magnetic field which is an additional significant nuisance for the patient. In addition there is the risk that the patient becomes claustrophobic due to the narrow interior and because he is generally required to lie on his back in the magnetic resonance device. The unpleasant feelings experienced by the patient are additionally made worse if a special head antenna is used for head examinations which surrounds the patient's head relatively tightly even in the field of vision. In the worst case scenario, especially during long examinations of half an hour or more, the examination has to be interrupted.
The closing-in situation experienced by the patient due to this head antenna is improved by the use of a double mirror which guides the patient's eyes in the direction of his feet. This gives a feeling of openness. The optical trick is certainly a little strange because the patient looks upward and then sees his feet.
From U.S. Pat. No. 5,412,419 an audio and video system is known, which can be used in an MR device without interference. With this system it is possible to divert the patient's attention during the image recording with an entertainment program.
Furthermore an audio visual headset from the company Resonance Technology Inc. in Northridge, USA, is on the market that includes MR-compatible headphones and MR-compatible eyeglasses. Here the entire arrangement of headphones and video eyeglasses is so compact that it can even be used inside a head antenna. The disadvantage exists here that the patient is disturbed by the video sequences that appear on the display. He may feel additionally insecure because he can no longer see anything that is going on outside.